Engineer Mikhail Venin works on an antenna for the Express AM8 new generation geostationary telecommunications heavy satellite at the large-sized transformed mechanical systems centre of the Reshetnev Information Satellite Systems company in the Siberian town of Zheleznogorsk April 2, 2014. The Express AM6 is a new generation satellite providing services including Russian governmental and presidential mobile communication, digital television and broadcasting, according to the Reshetnev company representatives. (Photo by Ilya Naymushin/Reuters)

A ballet student poses for a friend to take photos, at the national ballet school in Havana, Cuba, Thursday, December 12, 2019. The Soviet-style system that recruits children into a system of increasingly selective state dance schools has produced hundreds of elite dancers including Lorna Feijoo, Rolando Sarabia, Taras Domitro, Anette Delgado and Carlos Acosta. (Photo by Ramon Espinosa/AP Photo)

An injured fan is helped by a riot policeman during clashes between Red Star Belgrade and Partizan Belgrade fans in the stadium before the teams' Serbian Superliga soccer match in Belgrade, April 25, 2015. Serbian league leaders Partizan Belgrade held champions and bitter city foes Red Star to a 0-0 draw in a derby match marred by bad crowd trouble before kickoff on Saturday. The start was delayed for 45 minutes after home Red Star supporters pelted riot police with seats and flares, forcing officers to retreat from the north tier that houses the club's diehard fans. (Photo by Marko Djurica/Reuters)

The possible surface of TRAPPIST-1f, one of seven newly discovered planets in the TRAPPIST-1 system that scientists using the Spitzer Space Telescope and ground based telescopes have discovered. (Photo by Reuters/NASA/JPL-Caltech)

A student protester throws a stone against a riot police vehicle during a demonstration to demand changes in the education system in Santiago, Chile, April 21, 2016. (Photo by Ivan Alvarado/Reuters)

Burmese children attend classes at a government run school December 14, 2011 in Waw township, Myanmar. The education system is based on the United Kingdom's system, after nearly a century of British and Christian presences in Burma. (Photo by Paula Bronstein/Getty Images)

An Israeli missile is launched from the Iron Dome missile system in response to a rocket launch from the nearby Palestinian Gaza Strip, on March 12, 2012 near Ashdod, Israel. (Photo by Uriel Sinai/Getty Images)

A protester reacts as police use water cannon during a demonstration to demand changes in the Chilean education system in Santiago, Chile June 25, 2015. (Photo by Ueslei Marcelino/Reuters)